Rare-earth magnets are strong permanent magnets made from alloys of rare earth elements. Rare-earth magnets have significant performance advantages over ferrite or alnico magnets. There are two types of rare-earth magnets: neodymium magnets and samarium-cobalt magnets. The total world market for rare-earth permanent magnets is projected to be $17.2B by 2020, with China expected to control 74% (by tonnage) of this market. The rare-earth magnet segment of this market is expected to continue to grow and is predicted to account for approximately 30% of this total. Accordingly, the market and need for strong permanent magnets is substantial, whereas the supply is limited.
Fe16N2 has been identified as a potential alternative to rare earth metal magnets. FIG. 1a shows the performance (as indicated by the remanence, Br) as a function of density for α″-Fe16N2 and other classes of permanent magnet materials. A material with high performance and low density is desired because these are critical factors in achieving the system level goals of scalability and cost. The projected cost advantage of α″-Fe16N2 over other permanent magnet materials is shown in FIG. 1b. 
The limitation of the current state of the art is that 100% transformation to single-phase α″-Fe16N2—the phase that exhibits the outstanding magnetic properties—has only been accomplished by sputtering or evaporation in an environment supersaturated with nitrogen. However, when bulk powders or thin films are processed using traditional diffusion techniques, equilibrium thermodynamics limits the available nitrogen to <10.3 at % N. Thus, complete transformation of these powders has never been achieved in the reported literature, even using nano-scale starting powders.